Returning to the mapping of Meanings to Texts and vice versa, we should mention that, in contrast to common mathematical functions, this mapping is not unique in both directions, i.e., it is of the many-to-many type. In this section, we will discuss one direction of the mapping: from Meanings to Texts.
Different texts or their fragments can be, in the opinion of all or the majority of people, equivalent in their meanings. In other words, two or more texts can be mapped to the same element of the set of Meanings. In Figure IV.4, the Meaning M is represented with three different Texts T, i.e., these three Texts have the same Meaning.[18]
For example, the Spanish adjectives pequeño and chico are equivalent in many contexts, as well as the English words small and little. Such equivalent words are called synonymous words, or synonyms, and the phenomenon is called synonymy of words. We can consider also synonymy of word combinations (phrases) or sentences as well. In these cases the term synonymous expressions is used.
The words equivalent in all possible contexts are called absolute synonyms. Trivial examples of absolute synonymy are abbreviated and complete names of organizations, e.g. in Spanish ONU º Organización de las Naciones Unidas. Nontrivial examples of absolute synonymy of single words are rather rare in any language. Examples from Mexican Spanish are: alzadura º alzamiento, acotación º acotamiento, coche º carro.
However, it is more frequent that the two synonyms are equivalent in their meanings in many contexts, but not all.
Sometimes the set of possible contexts for one such synonym covers the whole set of contexts for another synonym; this is called inclusive synonymy. Spanish examples are querer > desear > anhelar: querer is less specific than desear which in turn is less specific than anhelar. It means that in nearly every context we can substitute desear or querer for anhelar, but not in every context anhelar can be substituted for querer or desear.
Most frequently, though, we can find only some—perhaps significant—intersection of the possible sets of contexts. For example, the Spanish nouns deseo and voluntad are exchangeable in many cases, but in some cases only one of them can be used.
Such partial synonyms never have quite the same meaning. In some contexts, the difference is not relevant, so that they both can be used, whereas in other contexts the difference does not permit to replace one partial synonym with the other.
The book [24] is a typical dictionary of synonyms in printed form. The menu item Language | Synonyms in Microsoft Word is a typical example of an electronic dictionary of synonyms. However, many of the words that it contains in partial lists are not really synonyms, but related words, or partial synonyms, with a rather small intersection of common contexts.